As a DNA-binding protein, OCT4 recognizes the cis-regulatory elements, that is the octamer motif (ATGCAAAT) or the TA-rich sequence, in the promoter or enhancer of target genes to regulate target gene transcription and then to activate or inhibit the activity of various signaling pathways, such as TGF-β1, Wnt/β-catenin/Snail, RTK/Ras/MAPK, Notch, Hedgehog, and PI3K/AKT/mTOR, finally promoting tumor development and progression [9, 18–20]. The gene discussed is SNAI1; the disease is neoplasm.